Digital BW, The Print

>Mark wrote-


>I'm new to the Piezo system so I'm having a hard time telling if the
>results I'm getting are normal or if I have a defective printer or am
>doing something wrong.

Snip


>My highlights
>are fine, but dots are very visible once the black ink kicks in when
>printing shadows (at least I think it is the black ink and not the
>dark gray ink).

I have noticed something similar in reprinting images (and ramps) 
with the PiezoTone WN inks that I had previously done with the 
original Piezo (Sundance) inks. The 50% to 85% range seemed "coarser" 
with the new inks. Rather like the difference between Rodinal grain 
and D-76 grain, crisp sandpaper as opposed to oatmeal. That is the 
"Cyan" position ink in Piezo laid over the "Magenta" (and "Yellow"?), 
not the Black.

The old ink warm/faded, the new doesn't. I suspect the dye or 
whatever that was in the old ink "bled" a bit and helped blend the 
pigment dots.

I've also had problems with using the old profiles with the new inks. 
The PhotoRag 188 profile seems a bit light in the lower "Magenta" 
position range. That makes the entry of the darker "Cyan" dots more 
apparent, and the "gaps" in the "Cyan ink" laydown seem lighter and 
thus more visible as "white dots" or grain. This cannot be eliminated 
with head alignment.

I saw this last week when I compared the "Proof of Piezography" test 
patches from a 7000/IP 5/MIS-FSN set-up with my 1160/Piezo/PT-WN, 
both on Photo Rag. The IP 5 dither was almost perfectly smooth 
throughout the scale, the Piezo "dots" visible at 50% and higher. No 
contest, and I also began to wonder if my 1160 was screwy.

Because of the poor profile, the 50% patch with PT-WN eyeballs equal 
to the 35% sector with FSN, so the "Cyan" transition at 55% is 
obvious. On the other hand, the 95%-60% Piezo range is darker than 
the IP-5 throughout, but the 100% D-max of the FSN K was higher than 
the Piezotone K (initial black formulation).

It would be interesting if there are any ink "collectors" out there 
who could measure the full strength density of the various quad sets 
by position. My hunch is the PiezoTone WN inks are darker in the Cyan 
position and/or lighter in the Magenta than the originals, and thus 
dark tones appear coarser or grainier.

The IP-5 FSN also had better highlight separation that the PT-WN, and 
the 7000/IP-5 easily resolved the 1/360 bars, the 1160 Piezo printed 
them solid. Youse gets what youse pays for.

I wouldn't generalize further until I get some (back-ordered) Museum 
Black and can install the Selenium set.

While Mark's 1200 is a six ink printer, Piezo is a quad process 
designed for the now ancient four ink 3000 and 1160. It seems crazy 
to still run just four inks on 6/7 ink printers. If IJM is 
redesigning Piezo from scratch, let's hope they do it in hex-tone.

"Let your mid-tones be dotless too..." might make a nice slogan
-- 
Bruce C. Kinch
Associate Professor of Photography
The Art Institute of Boston at Lesley University